Certified on Blockchain

Tracking presentation

Negative emission certificates 
We are working to allow anyone (not only companies and institutions but also individuals) to purchase Limenet negative carbon dioxide emissions certificates. Here we explain how we developed our tracking technology that uses blockchain and non-fungible tokens (NFTs) certified by third parties via MRV (Monitoring Reporting & Verification).

We use blockchain to be transparent

We have developed a model that uses blockchain to ensure maximum transparency and traceability in the monitoring of negative emissions. Through this tracking system, we will create a decentralized and virtual database that will record every step of the process, making every action, from the calcium carbonate quarry to the final certificate, visible and immutable.

Certification through NFT

To ensure maximum authenticity and customization, we will introduce non fungible tokens (NFT) certified by third parties via MRV (Monitoring Reporting & Verification). These NFTs represent negative emission certificates and are easily verifiable by anyone at all times. This gives a very high level of credibility to the actions of those who choose Limenet for carbon offsets. Within these certificates there will be all the information regarding the Limenet process.

The benefits of Limenet tracking

  • Maximum transparency towards the customer: we will offer our customers direct access to data in real time, allowing them to verify all the information. 
  • High traceability and reporting: each transaction will be recorded in an immutable way, facilitating the reporting and audit of activities. 
  • Elimination of double counting: thanks to the nature of the blockchain and the technology developed by Limenet,  the risk of duplicate negative emission counts will be avoided. 
  • Security and Authenticity: The use of high security standards and the use of third-party certified NFTs will ensure that our actions on the chain have true feedback in the real world. 
  • Scalability and efficiency: with the use of Polygon, we will guarantee an efficient management, above energy and environmental impact, even of large volumes of transactions. 
Limenet represents the future of sustainability for companies of all sizes. Our goal is to help create a cleaner, more beautiful, more livable world.

How it works

All instruments in our facilities will be connected to the blockchain’s decentralized network. Every operation, from the simplest to the most complex, will be recorded and stored permanently on blockchain through the Polygon network, a second layer of Ethereum known for its scalability and energy efficiency. 

Material preparation and identification

In our plant, calcium carbonate supplied by certified partners is subjected to a series of procedures to ensure maximum quality and traceability. Each production batch is labeled with a QR code containing key information such as origin, extraction date, associated CO₂ footprint and more. This preparatory step is crucial for the next steps. 
See the flow here

Blockchain tracking

Once the calcium carbonate batch enters the calciner, a "Smart Contract Tracking" (TSC) associated with it is recognized and created. This smart contract digitally represents the batch on the blockchain, keeping all relevant information publicly and unchangeably. Throughout the production process, data is collected by sensors and sent to the TSC for permanent storage on the blockchain. This guarantees maximum transparency and traceability.  In detail, during the tracking phase, the Limenet server, which has the task of overseeing the plant’s machinery, retrieves both the material information through the QR code and those from sensors scattered throughout the plant. All collected data is validated and stored permanently on the blockchain via the TSC of the batch being processed.
See the flow here

CO₂ production and storage

At the last stage, the TSC accumulated data from the sensors and recorded the chemical transformations of the material. Part of the calcium carbonate becomes calcium bicarbonate, which helps to compensate for the CO₂ emitted during production. The final phase of the TSC is the measurement of the actual CO₂, which reacts with slaked lime and produces calcium bicarbonate. This process is carefully monitored and each data is stored in the TSC on the blockchain. 
See the flow here

Negative CO₂ emissions

Every day, thanks to the operation of industrial plants, we generate negative shares of CO₂, represented by our TSC, which contain accurate data on the origin of each gram of carbon dioxide stored. To meet the needs of our customers and ensure the uniqueness of the share of CO₂ purchased, we transform the TSC in fungible tokens (NFT). Each NFT represents an amount of negative CO₂ purchased and, in addition to the basic information of the TSC, contains other data such as a brief description of the reason for the purchase, the name of the owner, external links on the monitoring and more.

Market of negative shares of CO₂

We generate daily quotas of CO₂ represented by our TSC, containing all the data of origin of every single gram of carbon dioxide that we store, but do not adequately represent our end customers who have heterogeneous needs. 

For this reason, in addition to containing TSC information, our NFTs will offer an extra personal touch: 

Personal Description: Each NFT will represent a unique ecological choice. You will be able to add a short description to share the story behind your share. Whether it’s a contribution to green projects or a personal commitment, you will be able to make your role in combating climate change tangible.

Personalized Identity: you will leave a trace of yourself in the world of sustainability. You will enter your name or nickname to identify yourself as an active supporter of the environmental cause. #climatedefender 

Additional Connectivity: If you are part of an environmental organization or want to share more information, you will use the “More” space to insert links or references. An effective way to make your environmental commitment known even more. 

Join us in embracing the challenge of sustainability through customization. Each NFT of CO₂ becomes a small chapter in a larger tale: our transition to a green and environmentally friendly future. Contribute your unique voice to this global narrative.

Additional insight


  • NFT
    An NFT, or Non-Fungible Token” is a unique digital certificate that proves the ownership of a digital object, such as an image, a video, a song or a share of CO₂ stored. Unlike cryptocurrencies like Bitcoin, which are interchangeable with each other in an equivalent way, an NFT is unique and cannot be replaced with another in a direct way. An NFT is therefore the digital proof of a unique property for digital or real objects.
  • Polygon
    Is a layer 2 blockchain network that aims to improve the capabilities of Ethereum. It is designed to solve some of Ethereum’s major problems, including scalability and high transaction costs. In simple terms, Polygon works as a “scalability layer” over Ethereum, allowing developers to create faster and more efficient decentralized applications. Improve Ethereum network performance without compromising security.
  • Ethereum
    Ethereum is one of the world’s leading decentralized blockchain and smart contract (smart contracts) platforms. It was created and launched in 2015 with the goal of extending the capabilities of blockchain technology beyond the simple management of cryptocurrencies, such as Bitcoin. Ethereum is designed to allow developers to create decentralized applications that automatically perform operations when certain criteria are met.
  • Smart contracts
    Smart Contracts are the backbone of blockchain-based technological innovation. Simply put, Smart Contracts are smart digital contracts: autonomous, secure and transparent.  Imagine that you have a traditional commercial agreement, but instead of relying on intermediaries or paper documents, everything happens automatically and unchangeably on the blockchain. Smart Contracts are computer programs that perform predefined conditions and actions when specific events occur. They are written in a special programming language and immutably recorded on the blockchain, ensuring the integrity and certainty of operations. How does this work? Let’s take a supply agreement as an example: once the parties involved meet the conditions, such as deliveries or payments, Smart Contracts come into action. Instead of having to rely on manual or intermediary procedures, the Contract Code ensures that transactions take place automatically only when all parties involved have fulfilled their obligations.  The are several advantages. Smart Contracts reduce the risk of human error, accelerate decision making and eliminate the need for expensive intermediaries. They also operate in a secure environment thanks to blockchain encryption, ensuring the privacy and protection of sensitive information.
  • Certified on Blockchain

  • Ethereum Energy Consumption Index
    To develop this project, we use Polygon blockchain, which uses the infrastructure and security systems of Ethereum, the most used and reliable blockchain, but with reduced costs. In fact, for everything that is written on a block of the chain, a fee must be paid for people who validate transaction. Since September 2022 Ethereum and Polygon change their validation system from the so called classic “proof of work” chain such as bitcoin to the innovative “proof of stake” that allows the use of much less energy-intensive machinery. So far, energy consumption drastically dropped making Ethereum one of the most promising blockchain in line with our business principles. In particular, as a result of this change, there’s no longer a network of energy-intensive mining devices competing with each other in order to create the next block for the underlying blockchain anymore. Instead, wealth plays a key role in the block creation process that makes use of PoS. Coins are locked up as collateral in the staking process (i.e. put “at stake”), in which the software then randomly selects a “staker” to create the next block for the blockchain. Regardless of whether a network runs PoW or PoS, creating the next block for the blockchain will provide the creator with a reward, but in PoW the chance of obtaining this reward could only be increased by employing more energy-hungry devices. PoS may only incentivize acquiring a higher stake to increase the odds of creating a new block, but the computational power of the underlying device is not relevant to this process. A participating device may still have to meet some requirements (e.g. storage capacity or bandwidth), but improving specifications will not yield more rewards. On the following figure, it is possible to see the annual energy consumption of proof of work (80-90 TWh/Year) and proof of stake system (0.01 TWh/Year) from September 2022.

  • Sustainability of Ethereum
    Despite PoS Ethereum presenting a significant improvement over PoW Ethereum with regard to the network’s electricity consumption, it is worth noting that blockchain technology in general is not energy-efficient compared to more centralized alternatives. Blockchains are distributed ledgers in which data and processes are replicated over hundreds or thousands of different nodes in the network, which introduces significant data redundancy. From a blockchain perspective this is required to make decentralization work (the more, the better), but from an environmental perspective this may always lead to undesirable outcomes. This can easily be illustrated by comparing the energy efficiency of PoS Ethereum to a centralized institution such as Mastercard as shown below. This comparison should serve as a reminder that decentralization always has a price; some will argue this feature is worth the cost.¹
  • Sustainability of Polygon
    We have opted to use the “eco-friendly” Polygon network because is a secon layer of Ethereum that uses proof of stake, which can tremendously reduce the amount of energy required to run the underlying blockchain. Based on 100 validators taking part in Polygon’s proof of stake network, it was estimated that “each transaction on Polygon produces just 0.206587559 grams CO₂,”² which is a long way from the 124.34 kilograms of CO₂ per transaction on the Ethereum network. Hence,is possible to establishes that there is a “limited environmental impact of minting NFTs on Polygon.”  In any case, the environmental impact of the chain, even if minimal, will be counted in the LCA.
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